Railway signaling system



Oct. 29, 1940. H. s. YOUNG V RAILWAY SIGNALING SYSTEM Original Filed Aug. 30, 1934 2 Sheets-Sheet 1 His (Ittomeg 0a. 29', 1940.. H, Y N 2,219,881

RAILWAY SIGNALING SYSTEM Original Filed Aug. 50, 1934 2 Sheets-Sheet 2 Bnventor Henry S. Yzmg.

[113 (Ittomeg Patented Oct. 29, 1940 UNITED STATES PATENT OFFICE-f RAILWAY SIGNALING SYSTEM Henry S. Young, Wilkinsburg,

The Union Switch & Signal Pat, "assignor to Company, Swiss.-

vale, Pa., a. corporation of Pennsylvania Original application August 30, 1934,

Serial N o.

be! 14, 1938, Serial No. 245,717

742,095. Divided and this application Decem- 16 Claims, (01.246-53) signal of the type described while the lamp is extinguished.

Another object of my invention is to provide a restrictive indication for trains approaching an approach lighted signal ,having a burned out lamp.

Other objects of my invention will appear as the description proceeds.

The present application is a division of my 1copending application Serial No. 742,095, filed August 30, 1934, now Patent No. 2,143,967, granted January 17, 1939, for Railway signalingsystems.

I shall describe one form of, signaling system embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1 and l are diagrammatic views which, when placed .end to end. with Fig. 1 on the right, show my inventionapplied to a signaling system employing an upper and a lower signal unit for eachsignal.

Similar reference characters refer to similar parts in each of the two views.

Referring to the drawings, the reference characters 1 and i designate the track rails of va stretch of railway track along which trafiic normally-moves in the direction indicated by the arrow. These'trackrails are divided by means of insulated joints 2 into a plurality of blocks, three of these blocks A'B, BC and CD being shown complete in thedrawings. Each of these blocks comprises a single track section, and each track section is provided with a track circuit including a battery 50 and a track relay TR. Located at the entrance end of each section is a signal S which, as here shown, comprises two signal mechanism units, each designated by the same reference character as the reference character -for the associated signal with a distinguishing subscript.

Each of these units, as here shown, is of the :type commonly known as a searchlight signal, and comprises an armature 5 mounted to rotate between an intermediate position to which it is biased, and two extreme positions. Each armature Sis controlled by an armature winding 6, and ispolarized by the field from a permanent magnet or an electromagnet (not shown) insuch a manner that when-thewinding 6 is energized, the armature 5 will rotate to its righthand or left-hand extreme position according as winding 6 is thensupplied withcurrent ,of normal or reverse polarity, respectively. Attached .to :each armature 5 to rotate therewith are three colored roundels G, R, and Y, whichare arranged to vbedisposed in the path ofxa bea of light projected from an associated lamp .L according as the armature 5 occupies its rightehand extreme position, its intermediate position or .its 'leftshand extreme position, respectively. For conveniencein illustration, each lamp L in-the drawing is shown disposed above the associated rounde'ls, but .itavill .be readily understood that in actual .practice each lamp will ;:be located directly back of the -associatedroundel and will have associated therewith :asuitable .optical system, not

shown, for projectinga beam .of {light from the lamp.

each indicate fproce d, stop or caution according as theroundel G, B, or Y is in.

The signals .3

front .of the associated lamp L when this lamp is lighted.'-- Y Operatively-eonnected with each armature 5 is acircuit controller comprising two movable contact fingers ;7.'an,d 8. The @movable contact finger 7 cooperates with a fixed-contact 7' to close ,a contact 7,7 when the armature occupies its right-hand extreme-position, and with a fixed contact 7 to close a contact ,7- 7 l when the armature occupies its intermediate position or its left-hand extreme position; while the movable contact finger 8 fcooperates with a fixed contact i8 pto close acentact 8+8 when the armature occupies its left-hand extreme position, and-withafix d contact 8 to close a contact 8-8 when the armature occupies its intermediate or its right-hand extreme position. Asignal of the type described is disclosed and claimed in Letters Patent of the Unit cd-;,States-No. 1,864,224, granted to Wesley .13. Wells, on;Jun e 21 1932, for Light signals.

In .actual practice, both signalmechanism ,units willusually be secured to the same pole-or ,raast with the one mechanism disposed aboyethe other.v With this arrangement, when both mechanisms are dis playing a revd aspect, the signal indicates stop;

when the upper mechanism displays a yellow aspect and the lower ,mechanism displays ;a,red aspect, the signalindicates caution when the upper mechanism displays a yellow aspectand the lower mechanism a .green aspect, the signal indicates approach restricting; and when the'upper mechanism displays a green aspectandthe lower mechanism a red aspect, thesignalindicates -pro,ceed.

Associated with each signal area polarized-distant relay DR, an approach lighting relay ALR, an auxiliary relay .AR, ;a reactor ,J, a signal repeater relay SE, a light-out relay 'LOR, a power-ofi-relay POR, .a :transformer' "11, and aa battery E. Each reactor J has the same reactance as the associated light-out relayLOR.

The winding :6 of each signal .mechzi'nism S is controlled byrthe associated track relay TR and by the associated distant relay- DR. Referring particularly .to the :winding 5541f signal mechanism 18*},

when track relay TR is energized and distant relay DR is energized in its normal direction so that its polar contacts are swung toward the left, as shown in the drawing, this winding is supplied with current 5 of normal polarity over a circuit which passes from battery Ee, through wires 180, 181,182 1 83 184 and 185, front contact 186 of track relay 'lR wires 187 and 188, polar contact 189-489 of relay DR wire 190, front contact 191-191 of relay DR wire 192, winding 6 of signal mechanism Sf, wire 194, front contact 1951 95 of relay DE 'wire 1.9.6, polar contact 197197 of relay DR and wires 198, 199 en,;ho'wev er,t'rack and 200 back to battery E v I relay TR is energized and distant relay :DR is energized in its reverse direction so that its polar contacts are swung towardthe right, winding 6 of signalmechanism S1 is then supplied with current of reverse polarity over a circuit which passes from battery E through wires 180, 181, 182, '183, 184 1 and 185, front contact 186 of track relay TR wires 187, 188 and 201,polarcontact197 -197 of relay DR wire 196,ifront contact'1-95- 195 of relay DE wire 194, winding 6 of signal mechanism 85*, wire 192, front contact 19'1-'191- of distant relay DR wire 190, polar-contact 189 189 of-distant' relay DR and wires 198,199 'and 200-back to battery E When trackrelay-TRAis energized and distant relayrDR is deenergized, winding 60f signalmechanism S', is then supplied with current of reverse polarity 'over-a circuit which passes-from battery E ythroughwires-180,- 181,182, 183,184 and 185, front contact 1 86 of-track relay TB wire 187, back contact 19.8-195 "of distant relay DR wire 194, winding 6 of signal mechanism Si, wire 1 92, back contact 191'191 of distant relay DR and wires 202, 198, 199 a nd 200 back to-batter'y E When winding 6 of signal mechanisms, is supplied with current of normal polarity, this signalmecha nism will, of course,'occupy the position in which the green roundel is disposed in front of the associated lamp L, and when winding of this signal mechanism is suppliedwith current'of reverse polarity, this signal mechanism will occupy the position in whichthe yellow roundel isdisp'osed 'in front of the associated lamp L. j v

' The winding 6 of each signal mechanism S is' controlled; by theassociated distantrelay' DR, by

the associated signal mechanism S 'by the associated track relayTR, and bythe associatedauxiliary' 150 relay AR. Referringparticularly to'winding 6 of signal mechanism S2, the circuit for this winding passes from battery E through wires 180 and 203,

front contact'204 of auxiliary relay AR wire 205,

front contact 206 of trackrelay- TR wire 207, 5 contact 88 of signal-mechanism Si, 'wire 17, contact 7'7 "of signal mechanism Si, wire- 208, polar contact 209--209 of'distant relay DR wire 210, front contact 211 of distant relay DR wire 212, winding'fi'of signal mechanism Si, wire 213', front contact '214 of distant relay DR ,-iwire 215, polar contact 21 6 21 6 of distant relay DB "and wires 217, 199 and 200 back toba ttery-E This "circuit is closed onlywhen track section"AB is unoccupied and signal mechanism Si 'is'swun'g to its left-hand extreme position, and the current suppliedto winding 6 of signal mechanism S; over this circuit isof such polarity that 'whenthis circuit is closed, the signal mechanism will be swung to the-positionv in which the green'roundel is disposed in front of the associated Each signal repeater relay SR'is controlledby the associated signal mechanisms; S and S by the associated track relay TR'and -by the associated auxiliary relay AR. "Referring particularlyito relay SR4, one circuit for: this relayi is closedwhene auxiliary relay SR and wires 199 and 200 back to battery E 'Another circuit for relay SR is closed when track relay TR. and auxiliary relay AR. are both enerigized and signal mechanisms S1 and S; occupy the positions in which the yellow and green roundels of these signal mechanisms are disposed respectively in front of the associated lamps Li and Lg, this latter circuit passing from battery E through wires 180 and 203, front contact 204 of auxiliary relay AR wire 205, front contact 206 of track relay 'TR wire 207, contact 8-8** of signal mechanism Si, wire 17, contact 7-7 of signal mechanism Si, wire 208, contact 77 of signal mechanism Si, wire 221, winding of relay SB and wires 199 and 200 back to battery E I At each signal location, there is provided a transformer designated by the reference character T with a suitable distinguishing exponent, and' a power-off relay designated by the reference character POR with a suitable distinguishing exponent. The primary winding 40 of each transformer T is constantly connected with the terminals Z and O of a suitable source of alternating current not shown in the drawing, while the secondary winding 41 of each transformer T is constantly connected with the winding of the associated power-off relay. It will be seen, therefore, that each power-off relay will be energized at all times except in the event that the alternating current supply fails.

Each distant relay DR is-controlledby the'associated track relay TR, by the signal repeater relay SR. associated with the two signalmechanisms S and S of the signals next in advance, by the track relay TB: associated with the signal next in advance, and by the'auxiliary' relay AR associated with the signal next in advance. Referring particularly to relay DR for example, one circuit for this relay passes from battery E through wires 180 and 203, front contact 204 of auxiliary relay AR wire 205, front contact 206 of track relay TR wire 207, contact 8'8 ofsignal mechanism Si, wire 222, winding of approach lighting relay ALR wire 233, front contact 224224"- of signal repeater relay SR line wire 22 5, front contact 226 of track relay TR wire 227, winding of distant relay DR line wire 251, front contact 228228 of relay SR and wires 229 and 200 back to battery-E Another circuit for relay DR. is similar to the circuit just traced with the"e'xception that this latter circuit includes back contacts 224224 and 228228 of signal repeater relay SR instead of front contacts 224224 and 228-'228 this relay. A third circuit for distant relay DR is similar to the circuit first traced for this relay with the exception that this latter circuit includes contact 7 7='of signal mechanism S? and wire 17 in place of contact 88 It will be noted that'each of the circuits for each distant relay includes the approach lighting relay associated with thesignal next in advance,- and it follows that each approach lighting relay will be energized exceptwhen the block next in therear of the associated signal, or the block next in advance of the associated signal is occupied.

Each lamp L isprovided with two energizing circuits one of which is closed when the associated approachlighting relay ALR is deenergized and the associated power-off relay'POR is energized, and

the other 'of which is--closed'- when the associa'ted approach lighting relay ALR and pcwer cfi *rela'y =POR "are both deenergize'd. Referrin'g particularly to lamp 135*, the circuit -fcr 'this lamp *w'lhich i's closed when approach lightingfrelay' is "deenergi'z'cd and power-oii 'relay 'POR is energi'z'ed may be traced from the right-hand terminal of secondary 41 of transformer "T through Wires 235,182, 1 83, 184, 236, the filament bf lamp' lli wire- Z-3 7, the Winding pf relay .LOR wire 238, -back eentac't 239-239 of approach lighting Telay}AI R w-ire 2'40, front -cntact =Z4 'l- Z l=T' :of power-01f relay POR and wire 242 to the lelt't 'hand' te'rm'inal' of secondary 41 of transformer T The circuitfor lamp L? which is closed when approach-li htin relay ALR and power-off relay-9011 "are both deenergized may 1 be trace'dgfrom battery E throug'h wires 1'80, 181, 1 82, "183, 1 84, and 236, lamp 12;, Wire 2 37,-the winding of light-out relay L QR Wire 238, back contact 239-239 of approach lighting relay ALR wire 240, back contact '=24"l= 241 of power-'ofi relay POR andwircs 22 9 and -200 -to battery E p Each lamp L is likewise provided with tw'o cire cuits one of which is clo'sed 'when -theiassociated approach lighting relay ALR is-dee'nergized and' th'e associated power-6H relay PORis energize'd and the other of which -is-closed when the asso'cia'ted approach lighting relay A LR is deenergized and the associated power-015:" relay PORis alsodeehergiz'ed. Referring particularly to lamp L3, -for example,'- the one circuit for this -lamp passes from the right-hand terminal of secondary 41 of transformer T 'throu'gh wires 235, 182, 18-3 and 243, 'the'filanientof -lamp Lg, reactorJ back contact o of approach lighting relay ALR' wire 240, "frontcontact-241 241 of power-(iii relay POR and wire-24 2 to the lefthand terminal of secondary '4-l of'transfcrme T The other circuit for lamp lag-may be -traced 'from battery E throng-h wires $80, 1-13 1 182, l 8 3- and 243, the filament of--1amp-I2;-, rea'ctor J back c'ontact250 of approachlig-hting'relay il LR wire 240, back contact 24 l'2l of power-01f LreIay POR and wires 229 and- ZO'O to-batte'ry EM 9 It will be noted that eachof the circuits for-the lamps L includes the winding of the associated light-out relay andthatthe one circuit is 'energ'ized by alternating curr'ent whereas the other cir'cuit *is energized by direct current. "Each li'glit out relay is'so constructedthat it will operate-on either-alternating ordirect "current, and theparts are' so proportioned' that when "eitherone of' the circuits for the associated-lampis closed, the relay will becom energized.

It 'will 'a'lso be noted-thateach of "the circuits for theflamp Li'includes areadtor J which as was previously pointed out has' the'sa'me reactance-as'the windingof theassociated light-out relay LGR It will further be noted that "the circ1iitsfor'the lamps L are supplied w'ithenergy from the 'same source's 'as the corresponding circuits for the lamps L and it follows thatboth 'lampswill be "suppliedwith' current of the same magnitude. I p Each auxiliary'relay "A 'Ris provided 'withtwo cir- 'cuits, one of which is closed when theassociated approach lighting relay is energized and "the associated light-out'rlay LOB. is deencrgiz'edfand the other of which is closed when the associated light-out relay is energized. Referring particularly to relay AR the F one -circuit for this relay includes the 'filamen'tof lamp Lfsand passes from "battery E through Wires 180, 181,182, l83,--l'84 an'd 236,, the filament of lamp Lfl 'wire-llil the winding of lightout relay EOR wire238,- front co'iitact239- -239 of approach lightingrelay'A ER =wire 2fl, b'aek contact 245- 2 4 S TOf li'ght-mit relay LOR wire 245, the winding-of relay AR andwire 2-47 'ba'ck to ib'attery E Thebther circuit for :relay AR passes from battery I), through wires 180, I81 and 182, front contact 245-245 of light-out relay LOR' wire 246, the winding of auxiliar reIayA R ,:a'n'd wire 24? back to battery E It will be noted that one "circuit for relay :AR ineludes the'winding of the associated light-'outirelay LOR, and the filament of the associateclvlamp L The resistance of each auxiliary relay AR is sufiiciently high so "that when this circuitis closed, "the associated light-out relay LOR 'will not open its back contacts, and'the lamp will not become lighted.

As shoWnin the drawing, blocks A B,--B+-C and G'"Dare all unoccupied, but the block to theright (if point -D is occupied by a train W. Track relays TR' T3 "and TR -are therefore all energized, but track relay TR 'is :deenergized. With track relay TR deenergized 'all circuits 'for the winding ctr signal-mechanism S? are interrupted at "front contact 186 of this track relay, and the sole circuit 'for winding "6 of signal mechanism S2 is openat front contact 206 of this track relay with the result that the r'ed roundels of bothsignal mechanisms S? and S aredisposed in front of the associatedlampsLf and LB. Furthermore, "with track relay TR, deenergized, all circuits for'relays DR DR SR and 'ALR are open 'so that these relaysare :all deen'ergized. Thepower-ofl relays PORare all energized, :and since power-oil" relay PORi is'energized and approach Llighting relayALR is deenergized, the circuits for lamps L2 and Ll} including the secondary 41 ofv transformer JDare both'closed. The lamps L? andLE are therefore both lighted so that signal S indicates stop. .Lig'ht-out-relayL0R is energized-by virtue of the circuit which is closed for lamp LL, and auxiliary relay A'R is therefore energized over the circuit including front contact '245-2.4'5' of relay LOR Tra'ck relay 'TR being energized and distant relay DE -being de'ener'gized, Winding '6 of signal mechanism'Si "is supplied with current of reverse polarity and winding 6 of signal mechanism Sgis deen'ergized. l The yellow roundel-of 'si g'nal mechanism-Sfis therefore dispose'd in front of the a'ss'ociatedlamp LE, and the red roundel of 'signal 'mechanism -Sg is disposed in front of the lamp Lg. 'With the signal mechanisms S? and S? in the positions just described, all

circuits for relay SR. are open, and this relay is therefore deenergized. Sincetrack r'ela'ys TR and TR are both energized-and relay SR is deenergized, j distant relay DR is -'energizedinthe reverse'direc- 'tion and approach lighting relay ALB. is therefore picked up.- Lamps-Lfand L; are'accordingly both extinguished and light-out relayLOR is deenergized. Auxiliary relay AR is energized'over the circuit including the filament of lamp Ilfifront 'contact 239-239 of relay AR and back wcontact; 245-245 of relay LOR With distant relay "DR "energized "in the reverse direction and'track relay TR energized, Winding 6 of signal mechanism 'Sfis supplied with current of reverse polarity and winding 6 of signaI mechanism S? is supplied with current of normal polarity; Signal mechanism Si, therefore, occupies its-extreme left-hand position in which the yellow r'ounde'l Y of'th'is mechanism is disposed in frontof the lamp L? and signal mechanism '8? occupies its extreme right-hand position in which-the green roun'del G of this latter mechanism is disposed in front of the lamp LE, *Signal mechanism S? and S? being in the positions qus't described, signal "repeater-"relay SR isenergized' anu sinee tracknelay 11R is also enera.

gized, distant relay DR is energized in the normal direction and approach lighting: relay vALR 'is picked up. Approach lighting relay ALB? being picked up, the lamps L? and L? are both deenergized, and light-out relay LOR -is also deenergized. With approach lighting relay ALR picked up andlightout relay LOR. deenergized, the circuit for auxiliary relay AR including the filament .oflamp .LP. is closed, and this latter relay istherefore also energized. Y

Distant relay DR being energized in its normal direction, winding 6 Eof signal mechanism Si ,is supplied with current of normal polarity, so that the green roundel of this signal mechanism is. in front of the lamp L1, and winding 6 of signal mechanism S3? is deenergized, so that the red roundel'of this mechanism is in front of the lamp L9. Approach lighting relay ALR v is energized, andall circuits for lampsL'} and L? are therefore open at the contacts 239-139 and .250 of relay ALR Lamps Li and L5 are therefore extinguished, and light-out relay LOB. is deenergized. The circuit for auxiliary relay ARA including back contact 245245 of light-out relay LOB. and 239- 239 'of approach lighting relay ALR is closed, and. this relayis therefore energized.- Relay SR is energized over the circuit includingfront contact 204 of relay AR and contacts 77" and 8 8 of signal mechanism Si.

With the apparatus in the position described, when the train W passes out of the section to the right of point D, track relay TR will pick up, thereby closing'its front contacts 186, 206 and 226. When front contact 1860f track relay TR becomes closed, a circuit for winding 6 of signal mechanism SP including this contact and back contacts 191-49 and 195-495 of distant relay DR will become closedand signal'mechanism SP will therefore move to its left-hand extreme position in which 1 110 the yellow roundel Y is disposed in front of the lamp Li. As soon as the signal mechanism. S? reaches this position, contact 88* of this mechanism will become closed, and will complete one of the circuits for distant relay DR thus causing this relay to become energized in its reverse direction and approach lighting relay ALRP to. pick up. When approach lighting relay ALR picks. up, the circuits which were previously closed for lamps L? and LE will become interrupted, and these lamps v will then become extinguished and light-out relay LOR will become :deenergized. The deenergization of light-out relay LOlEt will interrupt the circuit which was previously closed for auxiliary relay AR at front contact 245- -2450f relay LOR and 5 will complete the circuit for relayARPincluding back contact Z45-.24 5 of relay LOR Relay AR will not open itsfront contact 204 under these conditions, however, because of its slow releasing characteristic. 2 I

When distant relay DR. becomes energized in its reverse direction, in the manner justdescribed, .the circuit which'was previously closed for winding 6 of signal mechanism S? including back contact 195l95 and;l9l-l9l .of relay DR becomes in.-

, 65 terrupted, and another circuit for winding 6 .of signal mechanism S? including front contacts l95l 95 and 191-491 becomes closed. vSignal mechanism Sf will remain in the position shown, however, because the current supplied to the winding 6 of' this 0 mechanism over both of these circuits flows through the winding in the same direction. The energization ofidistant relay DR under the conditions just described, also completes thecircuit for winding 6 of signal mechanismSE, and whenthis circuitbecomes closed,

- 75 the mechanism moves to, its extreme right-hand position inwhich'the green roundel G is disposed in front of the lamp .Lg. The movement. of the signal mechanism .SE to the position just described completes the circuit forsignal repeaterrelay SR including front contact 7-.7 of signal mechanism S1, and relay SR. therefore picks up, and reverses the polarity of the current supplied to distant relay DR thuscausing this; relay to become energized in its normal direction. When relay DB. becomes energized in its normal direction, it interrupts the circuit which was previously closed for winding 6 of signal mechanism SE, and-this signal mechanism therefore moves to its intermediate .position in which the red roundel R is disposed in front of the lamp L When distant relay DR :becomes energized in its normal direction it alsointerrupts the-circuit which was previously closed ;for winding 6 of signal mechanism S? at polar contacts l 89- 189 and l97-l97 of this relay, andcompletes another circuit for winding 6 of signal mechanism S? including polar contacts 189-189- and l97 l97 of relay DR When this latter circuit for winding 6 of signal mechanism S? is closed, winding 6 is then supplied with current of normal polarity, and the-mechanism of signal Si therefore moves to the position in which the green roundel G is disposed in front of the lamp L1. The movement of the two signal mechanisms S? and S? from the position in which they are shown in the drawing to the positionjjust described, interrupts one circuit for relay SR and completes the other circuit for this relay, but due to the slow releasing characteristic of relay SR this relay does not open its front contacts under this condition.

I shall now assume that the I parts are in the position shownin the drawing and that the filament of-lampv L? becomes interrupted for some reason. Under this condition, the circuit which was previously closed for auxiliary relay AR will become interrupted at the lamp filament, and this relay will therefore becomev deenergized and open its front contact204. The openingof this contact will interrupt the circuit which was'previously closed for distant relay, DRB, thus causing this relay and approach lighting relay ALB. to become deener gized. The; ,deenergization of. approach lighting relay, ALB? will. complete one of the energizing circuits, for lamp Lg, thus causing this lamp to become lighted. The deenergization of relay DR will interrupt the circuit which was previously closed for winding-6 of signal mechanism SF including contacts l95195 and l9ll 9l of relay DR and willcompletethe circuit for winding 6 of signal mechanism- Sf including contacts 'l95l95 and This signal mechanism, however, will-remain in the position shown since the current supplied to-the winding 6 over both of these circuits flows through the winding in the same direction. The deenergization of relay DR will also interrupt the- ,circuit which was previously closed for windingfi of signal mechanism S? at front contacts Zlland 214 of this relay, and this winding will therefore now become deenergizd, thus causing signal mechanism S? to move to the position in which the red roundel R is disposed in front of the lamp Lg. When signal mechanism SEmoves to this latter position, the opening of contact 7-7 of this signal Ymechanism. will deenergize signal repeater relay SR3 and this relay will therefore reverse the polarity of 1 the current supplied to distant relay DR thus causing signal mechanism S to move from the. position shownto the position in which the yellow roundel Y is disposed at the front of the lamp- Lfiand the signal'mechanism S; to move from the position shown to :theposition in which the green roundel G is disposed in front of the associated lamp L, of a signal burnsont whenthe. block next in advance is occupied by a train, thezsignal mechanisms of the signal for the. block next in rear will automatically be moved to such positions that if the associated lamps were then lighted due to the presence of a train in the second block in the rear,

the signal for the block next in rear would then.

display a caution indication. It will also be seen that if the lamp L; of a signal burns out when. the

block next in advance of the associated block is occupied by a train, the signal mechanisms of the signal for the second block in rear. of the section in question willautomatically be moved to, such positions that if the associated lamps were then lighted due to a train approaching the signal, the signal would display an approach restricting. indication. 'It

follows that under either of. the conditions just;

described, an engineman approaching a 'signal in which the lamp L is burned out. willreceive the same indications when he passes the two. signals next in the rear of the signal having-the burned out lamp as he would receive if the .block immediately in advance of the signal having the burned out lamp were occupied, thus giving him ample opportunity to stop when he finally approaches the signal'with the burned out lamp.

I shall next assume that with the parts in the position in which they are shown in the drawing, the

lamp L? burns out; Under this condition, auin'liary,

relay AR will become deenergized and will interrupt the circuit which was previouslyclosed at the contact.

of this relay for winding 6 of signal mechanism St, thus causing this signal mechanism to move from the position in which the green roundel G is disposed in front of the lamp L? to the position in which the red; roundel R is disposed in front of this lamp. When. signal mechanism S? moves to this latter position,

' the circuit which was previously closed for relay SR will become interrupted so thatthis relay will become deenergized but the deenergization ofthis relay. will have no effect on theapparatus because all circuits for relay DR will then be openat front contact 204 of relay AR and relay DR will already be deenergized. The deenergization of relay DR will cause. signal mechanism Sf to move from the position shown to the position in which the yellow roundel Y is disposed in front of the lampLg. -As a result, if atrain now enters the'block to the. left of block AB and causes approachlighting relay ALR to become deenergized, signal S will indicate caution-instead of proceed. It, follows that if signal lamp L burns out when the two blocks next in advance of the associated signal are both unoccupied, the. signal mechanisms of the signal next in the rear of the associated signal will be automatically moved to the. same positions as when a lamp burns out, and the block next in advance of the associated signal is occupied. I Although I have herein shown and described only one form of signal system embodying. my invention, it is understoodthat various changes and modifications may be made, therein within the scope of the appended claims without departing fromthe spirit and scope of my invention.

Having thus described my invention, what'I claim I. In combination, a stretch of railway trackdivided into blocks, a signal for governing the "entrance of trafiic into each block comprising an upper and a lower signal mechanism each including an electric lamp and each responsive to' the polarity of the current supplied thereto, each said signalbeing capable of displaying stop-when the. associated mechanismsare both deenergized, caution when the'upper mechanismjssupplied with current of. reverse polarity and thelower'mechanism is -deener-. gized, approach. restricting when the upper mechanism is supplied with current of reverse polarity and the lower mechanism is supplied with current of normal polarity, and proceed when the upper mechanism is:supplied with current of normal polarity and the lower mechanism is deenergized; means for normally-supplying the upper mechanism I of each signal with current of normal polarity when the next three blocks in advance are unoccupied and with current of reverse polarity when either one or twoblocks next in advance are unoccupied, means for supplying the lowerwinding of each signal with current of normalpolarity when and only when the two blocks next in advance are unoccupied, means for lighting the lamps associated'with a signalwhen a train occupies the block next in the'rear or next in advance ofthe signal, and means effective if the filament of the lamp associated with the upper mechanismsof a signal is broken and no train is approaching the signal or occupies the block next in advance thereoffor conditioning the two signals next in the rear to display more restrictive indications.

2. In combination a. stretchxof railway track divided into blocks, atrack circuit for each block. including a track relay, a signal for governing the entrance of traflic ,intoeach block, comprising an upper anda lowerysignal mechanism each including an electric lamp and each responsive to the polarity of the currentsupplied thereto, each said signal being capable; of displaying stop when the associated mechanisms are bothdeenerg'ized, caution when the upper mechanism is supplied with current of reverse polarity and the lower mechanism is. deenergized, .approach restricting. when the upper mechanism is supplied with current of reverse polarity andthe lower mechanism is supplied with current of normal polarity, and proceed when the upper mechanism is-supplied with current of normal polarity and the. lowerme'chanism is. deenergized; an approach lighting relay, :a light-out relay, a slow releasing auxiliary relay, a slow releasing signal. repeater relay,.and.a.polarized slow releasing distant relay for each signal,. each polarized distant relay being provided with normaland-reverse polar contacts which .becomeclosedaccording. as the relay is supplied with current of normal or reverse polarity and subsequently remain closed until the polarity of the current supplied to the frelayis reversed, and

with neutral contacts'which' are closed whenever the relay issuppliedwithcurrent of. either normal or reverse polarity; means for supplyingthe upper .mechanism of each signal with current of normal upper signal mechanism occupies. its caution position and the. associateddistantrelay is supplied with current of'normal polarity; a circ'uitfor each distant relay including a-front contact of the associated track relay, pole-changing contacts of the signal repeaterrelay associated with the signal next in advance of the associated signal, the winding of the approach lighting relay for the signal next in ad- Vance, contacts controlled by theupper mechanism of the signal next in advance, afront contact'of the track relay associated with the signal next in advance, and a front contact of the auxiliary relay associated with the signal next in advance; a circuit for each signal repeater relay controlled by both signal mechanisms of the associated signal, by'the' current of normal polarity, the'upper mechanism of the associated signal is energized by current of reverse polarity, the associatedtrack relay is energized and the associated auxiliary relay is energized; another circuit for each signal repeater relay controlled by the upper signal mechanism of each signal and by the associated track and auxiliary relays, and closed when the upper mechanism of the associated signal is supplied with current of normal polarity and the associated track and auxiliary relays are both energized, means for energizing each auxiliary relay in series with the lamp of the upper signal mechanism of the associated signal and the winding of the associated light-out relay when the associated approach lighting relay is energized and the associated light-out relay is deenergized, means for energizing each auxiliary relay when the associated approach lighting relay is energized, means for energizing the'lamp ofthe upper mechanism of each signal in series with the associated light-out relay when the associated approach lighting relay is deenergized, and means for energizing the lamp of the lower mechanism of each signal when the associated approach lighting relay is deenergized.

3. In combination with a section of railway track, a light signal for governing the entrance of trafllc into said section, said signal having a lamp, a polar ized line relay for governing the indication provided by said signal in accordance with the polarity of the current supplied thereto, a polarized line circuit for said line relay supplied .with current of one or another polarity in accordance with trafiic conditions in advance, a checking relay for said signal, an energizing circuit for said checking relay including the lamp filament of said signal but incapable of lighting said lamp, and means controlled by said checking relay effective upon the interruption'ofthe flow of said checking current due to failure of said filament for controlling the traffic approaching said section.

4. In combination with a section of railway track, a

a light signal for governing the entrance of trafiic into said section, said signal having a lamp, a polarized line relay for governing the indication provided by said signal in accordance with the polarity of the current supplied thereto, a polarized line circuit for said line relay supplied withcurrent of one or another polarity in accordance with traflic conditions in advance, a checking relay for said signal, an energizing circuit for said checking relay including the lamp filament of said signal but incapable of lighting said lamp, and means controlled by said checking relay efl ective upon the interruption of the flow of said checking current due to failure of said filament for causing said signalto display a restric tive indication irrespective of traific conditions in advance thereof. i

5. In combination, a stretch of railway track divided into blocks, a light signal for each block for governing traflic entering therein, each of said signals having a lamp, a polarized line relay for each signal for governing the indication provided by the signal in accordance with the polarity of the current supplied thereto, a polarized line circuit for each line relay supplied with current of one or another polarity in accordance with trafiic conditions in advance, a

of the associated signal butincapable of lighting said lamp, and means governedby each checking relay and effective upon failure of the lamp filament of the associated signal for controlling the line' circuit for the linerelay -associated with the signal next in the rear. v

6; ln combination, a stretch of railway track' divided into blocks, a light signal for each block for governing traflicentering -therein, 'each of said'signals having a lamp, a polarizedline relay for each signal-for governing the'indication provided by .the signal in accordance with the polarity of the current supplied thereto, a' polarized line circuit for each line relay supplied with current of one or another polarity in accordance with traffic conditions in adv'ance,a checking relay for each signal, an energizing circuit for each checkin'g relayincluding the'lamp filament of the associated-signal but incapable of lighting said lamp, a normally energizedapproacli lighting relay for each signal," means governed by each checking relay and effective upon failure of the lamp -filament of the associatedsignal for controlling the line circuit for the line relay associated with the signal next in the rear and for deenergizing 'saidapproach lighting relay, and means effective'when said approach lighting relay is'deenergized for causing the associated signal to displaya restrictive indication irrespective of trafiic conditions in' advance thereof.

7. In combination with'a section of railway track, an approach energized light signal for governing traffic entering saidsection, 'said signal having a lamp, a polarized line relay for said signal for governing the indication provided by the signal, a polarized line circuit for said relay controlled by traffic conditions in advancefof'said signal, means for at times supplying lighting current to said signal, means for at other times supplying a checking current of insufficient value to light said signal, and' means ease tive upon an interruption in said checking current in the event of failure of'the lamp of said signal for controlling the traffic approaching said section.

8. In combinatiomfa stretch of railway track divided into blocks,an approach energized light signal for each blocli '-'for' governing traific entering therein, each of said signals having'a lamp,a polarized relay-for each signalfor governing the indication provided-thereby,alighting' circuit for each signal, fa normally energized checking circuit for each signal including' thelamp filament but ineifect-' in advance.

9. In combination, a stretch of railway 'track divided into blocks, an approach energized light signal for each ,block for governing traific entering therein, each of said signals having a lamp, a polarizedrelay for each signal for governing the indication provided thereby, a normally energized approach lighting relay for each signal governed by traffic approaching the signal and effective when deenergized to cause the signal to become lighted, a normally energized checking relay for each signal, a circuit for each checking relay including a front contact of the associated approach lighting relay and the lamp filament of the associated signal, and a line circuit for each polarized line relay including a front contact of the checking relay next in advance.

'10. 'Inco'mbination, a stretch of' railway track divided into blocks, an approach energized light signal for each block [for governing trafiic entering therein, each of said'signals'having a lamp, a polarized relay'for each signal for governing the indication provided thereby, a normally energized approach lighting relay for each signal governed by traflic approaching the signal, a normally deenergized light-out relay for each signal, a normally energized checking relay for each signal, a lighting circuit for each signal including a back contact of the associated approach lighting relay and the winding of the associated light-out relay; a circuit for each checking relay including a back contact of the associated light-out relay, a front contact of the associated approach lighting relay, and the lamp filament of the associated signal; and a line circuit for each polarized line relay controlled by the checking relay for the signal next in advance.

11. In combination with a section of railway track, a light signal for governing trafiic entering said section, said signal having a lamp, a polarized line relay for said signal for governing the indication provided by the signal, a polarized line circuit for said relay controlled by trafiic conditions in advance of said signal, means for at times supplying lighting current to said signal, a checking relay, a checking circuit including the lamp filament of said signal for at other times supplying a checking current to the signal and for energizing said checking relay, a slow acting relay controlled over a contact of said checking relay, and a line circuit controlled by said slow acting relay for governing tralfic approaching said signal.

12. In combination with a section of railway track, an approach energized light signal for said section comprising a main and an auxiliary light unit, a polarized line relay for each signal for governing the indication provided by the signal, a polarized line circuit for said relay controlled by trafiic conditions in advance of said signal, means for at times supplying lighting current to said signal, means for at other times supplying a checking current to the main unit of said signal of insufiicient value to light the lamp of said main unit, and means effective upon the interruption of said checking current in the event of failure of said lamp for lighting the lamp of said auxiliary light unit.

13. In combination with a section of railway track, a signal for governing trafiic entering said section including a mechanism and a lamp, means governed by trafiic conditions in advance for opereach signal connected in series with a source of energy and the signal l'amp filament, a control relay for each signal controlled by contacts of its signal and in turn connected to pole change the line circuit to the signal to the rear, and a front point of the check relay in the energizing circuit of the control relay.

15. In a railway signaling system, in combination, spaced signals each having an incandescent lamp, a

I polarized line circuit for controlling the indication displayed by each signal, a filament check relay at each signal connected in series with a source of energy and the signal lamp filament, a control relay for each signal controlled by contacts of its signal and in turn connected to pole change the line circuit to the signal to the rear, and a front contact of the check relay in the line circuit to the signal to the rear..

16. In a block signaling system, signals of the movable color screen type having contacts operated by said screen in accordance with the indication displayed by the signal, a track circuit next in advance of each signal and having a track relay, a polarized line circuit associated with each signal for controlling the signal next in the rear, and means associated with each signal and at all times including and dependent upon the contacts of two slow release relays controlled by the contacts of that signal and the track relay for that signal for at all times controlling the continuity and polarity of energization of said line circuit for the signal next in the rear.

HENRY S. YOUNG. 

